Submental Surface Electromyographic Measurement and Pharyngeal Pressures During Normal and Effortful Swallowing

Physiology and Execution of Swallowing Maneuvers in 3D Videos: Integrating the Technology into Patient Care

Educational technologies have proven to be an effective way to guide and educate patients, allowing them to increase awareness of their dysphagia condition and how treatment will help them. In this sense, this study aimed to develop and validate the content and appearance of 3D iconographic videos, which addressed the physiological demonstration and execution of protective and facilitating swallowing maneuvers, as well as verifying the feasibility of its use in teleconsultation, having adults and elderly people with oropharyngeal dysphagia as the main target audience. The development of the 3D videos was elaborated based on a guiding scientific script, constructed from an integrative literature review. After the development of the 3D videos by the digital designer, a committee of 12 expert judges evaluated the material produced to validate the content and appearance where a minimum agreement index of 0.8 among the judges was considered satisfactory. Subsequently with the validated material, the proof of concept was conducted together with the target population of 10 dysphagic patients through individual teleconsultation via Google Meet platform. After the teleconsultation, patients responded to a Google Forms questionnaire, analyzing the videos presented. From the integrative literature review, 29 studies that contained relevant information about the physiological effects caused by swallowing maneuvers were selected. Based on this information, the scientific script was created, allowing a detailed description of the physiological events that occurred during swallowing while executing the maneuvers. With the finished script, 3D videos of swallowing maneuvers were produced. After developing the material, the committee of expert judges validated the content and appearance. The twelve items that had an agreement index below 0.8 were adjusted. Once the adjustments were completed, the videos were analyzed again, obtaining approval from the judges, and ensuring the validation of content and appearance of the material developed. A proof of concept was conducted on ten dysphagic patients. The maneuver applied was chosen according to the patient's physiological changes, causing only 4 of the 9 maneuvers to be tested, as the patients did not demonstrate changes in swallowing that would justify the use of the other maneuvers. After this, patients answered a form in which all items covered received positive evaluations, related to both ease of understanding and learning. This study allowed the development of the 3D videos with a didactic demonstration of the physiology and execution of protective and facilitating swallowing maneuvers, in addition to having its content and appearance validity assured through analysis by the committee of expert judges.

Difference in the Electromyographic Behavior of the Masticatory and Swallowing Muscles During Cued Versus Spontaneous Swallowing

The risk of dysphagia and/or aspiration is determined using screening tests, such as the repeated saliva swallowing test and modified water swallowing test, which evaluate cued swallowing. However, humans masticate and swallow foods with various consistencies, forms, and amounts, without conscious awareness. Therefore, this study aimed to examine the difference in the behavior of masticatory and swallowing muscles during spontaneous versus cued swallowing through a series of mastication and swallowing processes by evaluating surface electromyogram (sEMG) signals. The effect of the consistency and amount of food on the behavior of these muscles was also investigated. The sEMG recordings of the masseter muscles and anterior belly of the digastric muscle for 12 subjects, and genioglossus muscle for 5 subjects were obtained. The genioglossus activity was recorded using custom-made ball electrodes. The test foods were cookies and tofu, in amounts of 2 g and 4 g. The normalized muscle activity (integrated EMG), duration of the muscle activity, initial activation timepoint of each muscle, and total duration of swallowing were compared among four conditions. The activity of each muscle was significantly higher during the swallowing of cookies than tofu, for 4 g vs 2 g, and for cued versus spontaneous swallowing. The duration of each muscle activity, initial activation timepoint, and total duration of swallowing were significantly longer for cookies versus tofu, for 4 g vs 2 g, and for spontaneous versus cued swallowing. These results suggest that the behavior of the masticatory and swallowing muscles is affected by cued swallowing and by the consistency and amount of food.

Evaluating Anterior and Posterior Oral Tongue Contributions to Pressure Generation: A Comparison Between Regular and Effortful Saliva Swallows

PURPOSE

This study determined the contributions of the anterior and posterior tongue regions in tongue pressure generation during regular saliva swallows (SSs) and effortful swallows (ESs) completed under two different instructions. The association between tongue pressure and perceived effort to swallow was also examined.

METHOD

Forty healthy adults without swallowing disorders participated in this study, divided into two age groups: 20 younger (Mage = 21.95 years, SD = 4.43) and 20 older (Mage = 70.10 years, SD = 4.30). Simultaneous data acquisition involved submental surface electromyography, tongue manometry, and a visual analog scale across swallowing conditions (SS, ES with tongue emphasis, and ES with pharyngeal squeezing). The main outcome measures were tongue pressure during swallowing and perceived effort to swallow.

RESULTS

Overall tongue pressure during ESs with tongue emphasis and with pharyngeal squeezing was greater than that during SSs (R2 = .78, p < .001). Moreover, tongue pressure during the ES with tongue emphasis was greater than that during the ES with pharyngeal squeezing (t = 25.63, p < .001). The posterior tongue region generated more pressure during SSs (R2 = .64, p < .001) and the ES with tongue emphasis (R2 = .55, p < .001) than the anterior tongue. Finally, a positive correlation was found between perceived effort and tongue pressure during swallowing (r = .75, 95% CI [0.72, 0.77]).

CONCLUSIONS

Tongue pressure generation was affected by the type of instruction used to elicit ESs, and the posterior tongue showed relatively greater pressure contributions than the anterior tongue for ESs with tongue emphasis and SSs. Furthermore, age-related declines in pressure generation during swallowing were not evidenced in this study, underscoring the ability of healthy older individuals to appropriately modulate lingual pressure during ESs. Last, our results showed that the visual analog scale is a simple tool for rating swallowing effort during ESs, supporting its potential clinical use to train ESs.

Comparison of Submental Surface Electromyography during Dry Swallow between Irradiated Head and Neck Cancer Survivors and Normal Individuals

INTRODUCTION

This study compared the submental surface electromyography (sEMG) duration and amplitude during dry swallowing between irradiated head and neck cancer (HNC) survivors and age-matched normal individuals. Further, the relationship between submental and infrahyoid sEMG in the irradiated HNC group was explored.

METHOD

Forty participants (20 HNC survivors and 20 age-matched normal individuals) participated in this study. The HNC survivors had completed organ preservation cancer treatment (at least 1-month post-treatment). They were on a complete oral diet without enteral supplementation (FOIS score> 4). Submental and infrahyoid sEMG activity was calculated for three trials of saliva swallow for each participant using sEMG. The duration and amplitude parameters considered were: onset duration - duration from the onset of swallowing to the maximum amplitude, offset duration - duration from the maximum amplitude to the end of the swallowing activity, total duration, and maximum amplitude.

RESULTS

The study found that irradiated HNC survivors exhibited prolonged temporal measures, particularly in the offset duration, which suggested a delayed descent of the hyolaryngeal complex during swallowing. Additionally, the HNC group showed a positive correlation between submental and infrahyoid sEMG. Furthermore, it was observed that the rate of increase in the duration of submental sEMG during subsequent swallowing was greater in HNC survivors which could be due to reduced salivation.

CONCLUSION

Compared to age-matched normal individuals, irradiated HNC survivors manifest alterations in the submental muscle activities during dry swallowing as measured using sEMG. The temporal and amplitude changes are likely to have arisen as a consequence of postradiation changes.

Surface Electromyographic Activity of the Masseter Muscle During Regular and Effortful Saliva Swallows: A Preliminary Study

Biofeedback is a critical component in motor learning of new, complex behaviors such as modifications to swallowing. Surface electromyography (sEMG) is a commonly employed biofeedback tool in swallowing management to assess muscle activity patterns, determine amplitude and duration of swallowing, and train swallowing strategies such as the effortful swallow (EFS) maneuver. The EFS can potentially change multiple physiological components of the swallowing process such as pressure generation and movement of biomechanical structures. The purposes of this study were to determine whether the masseter muscle could differentiate a normal swallow (NS) from an EFS and whether there was a relationship between perceived muscle effort used to swallow and objective measures of muscle activity. Twenty healthy young adults participated in this study. Masseter sEMG peak amplitude and duration were measured across five regular saliva swallows and five effortful saliva swallows. Additionally, participants rated their perceived swallowing effort using a visual analog scale (VAS). Two swallowing conditions, NSs and EFSs were compared with hierarchical models, and repeated measures correlation was used to determine the relationships between the VAS and sEMG peak amplitude. Participants produced swallows with greater masseter sEMG peak amplitude and duration during the EFS. Moreover, a positive correlation was identified between perceived swallowing effort and masseter sEMG peak amplitude. These findings support the potential use of the masseter muscle to differentiate NSs from EFSs and implement the VAS during therapy for tracking patients' performance, particularly in settings with limited access to sEMG.

Hyolaryngeal Movement During Normal and Effortful Swallows Determined During Ultrasonography

PURPOSE

This study investigated (a) the effects of the effortful swallow under two different instructions (tongue emphasis vs. pharyngeal squeezing) on hyoid displacement and hyoid-larynx approximation, (b) the association between tongue pressure and hyolaryngeal movement during normal swallowing and the effortful swallow produced with tongue emphasis, and (c) age-related differences in hyolaryngeal movement during normal and effortful swallows (tongue emphasis vs. pharyngeal squeezing) in healthy individuals.

METHOD

Forty healthy adults (20 younger and 20 older) swallowed their saliva as they normally do (normal swallow) and performed the effortful swallow with tongue emphasis and pharyngeal squeezing. Tongue-to-palate pressure during swallowing was measured using the Iowa Oral Performance Instrument, hyolaryngeal movement was measured using ultrasonography, and submental surface electromyography was used to track swallows.

RESULTS

Results revealed differences in hyolaryngeal movement across swallowing types. Both types of effortful swallows showed greater hyolaryngeal movement than normal swallows. Additionally, hyolaryngeal movement was greater during the effortful swallow with tongue emphasis than the effortful swallow with pharyngeal squeezing. Age-related differences were found only in hyoid-larynx approximation during the effortful swallow with tongue emphasis (younger > older adults). Furthermore, moderate positive correlations were identified between tongue pressure and hyolaryngeal movement during normal swallows and the effortful swallow with tongue emphasis.

CONCLUSIONS

The findings show that varying instructions of the effortful swallow affect hyolaryngeal movement differently, suggesting that clinicians may need to individualize the effortful swallow instruction according to the physiological impairments of each patient. Additionally, natural age-related changes in swallowing physiology do not seem to affect an individual's ability to perform the effortful swallow or to impact hyolaryngeal movement. Finally, the association between tongue pressure and hyolaryngeal movement during normal swallows and the effortful swallow with tongue emphasis suggests that the tongue plays a critical role in swallowing, priming subsequent swallowing events.

Toward a robust swallowing detection for an implantable active artificial larynx: a survey

Total laryngectomy consists in the removal of the larynx and is intended as a curative treatment for laryngeal cancer, but it leaves the patient with no possibility to breathe, talk, and swallow normally anymore. A tracheostomy is created to restore breathing through the throat, but the aero-digestive tracts are permanently separated and the air no longer passes through the nasal tracts, which allowed filtration, warming, humidification, olfaction, and acceleration of the air for better tissue oxygenation. As for phonation restoration, various techniques allow the patient to talk again. The main one consists of a tracheo-esophageal valve prosthesis that makes the air passes from the esophagus to the pharynx, and makes the air vibrate to allow speech through articulation. Finally, swallowing is possible through the original tract as it is now isolated from the trachea. Yet, many methods exist to detect and assess a swallowing, but none is intended as a definitive restoration technique of the natural airway, which would permanently close the tracheostomy and avoid its adverse effects. In addition, these methods are non-invasive and lack detection accuracy. The feasibility of an effective early detection of swallowing would allow to further develop an implantable active artificial larynx and therefore restore the aero-digestive tracts. A previous attempt has been made on an artificial larynx implanted in 2012, but no active detection was included and the system was completely mechanic. This led to residues in the airway because of the imperfect sealing of the mechanism. An active swallowing detection coupled with indwelling measurements would thus likely add a significant reliability on such a system as it would allow to actively close an artificial larynx. So, after a brief explanation of the swallowing mechanism, this survey intends to first provide a detailed consideration of the anatomical region involved in swallowing, with a detection perspective. Second, the swallowing mechanism following total laryngectomy surgery is detailed. Third, the current non-invasive swallowing detection technique and their limitations are discussed. Finally, the previous points are explored with regard to the inherent requirements for the feasibility of an effective swallowing detection for an artificial larynx. Graphical Abstract.

A robust HD-sEMG sensor suitable for convenient acquisition of muscle activity in clinical post-stroke dysphagia

Objective.A flexible high-density surface electromyography (HD-sEMG) sensor combined with an adaptive algorithm was used to collect and analyze the swallowing activities of patients with Post-stroke dysphagia.Approach.The electrode frame, modified electrode, and bonded substrate of the sensor were fabricated using a flexible printed circuit process, controlled drop coating, and molding, respectively. The adaptation algorithm was achieved by using Laplace and Teager-Kaiser energy operators to extract active segments, a cross-correlation coefficient matrix (CCCM) to evaluate synergy, and multi-frame real-time dynamic root mean square (RMS) to visualize spatiotemporal information to screen lesions and level of dysphagia. Finally, support vector machines (SVM) were adopted to explore the classification accuracy of sex, age, and lesion location with small sample sizes.Main results.The sensor not only has a basic low contact impedance (0.262 kΩ) and high signal-to-noise ratio (37.284 ± 1.088 dB) but also achieves other characteristics suitable for clinical applications, such as flexibility (747.67 kPa) and durability (1000 times) balance, simple operation (including initial, repeated, and replacement use), and low cost ($ 15.2). The three conclusions are as follows. CCCM can be used as a criterion for judging the unbalanced muscle region of the patient's neck and can accurately locate unbalanced muscles. The RMS cloud map provides the time consumption, swallowing times, and unbalanced areas. When the lesion location involves the left and right hemispheres simultaneously, it can be used as an evidence of relatively severely unbalanced areas. The classification accuracy of SVM in terms of sex, age, and lesion location was as high as 100%.Significance.The HD-sEMG sensor in this study and the adaptation algorithm will contribute to the establishment of a larger-scale database in the future to establish more detailed and accurate quantitative standards, which will be the basis for developing more optimized screening mechanisms and rehabilitation assessment methods.

Effect of the Effortful Swallow on Pharyngeal Cavity Volume: Kinematic Analysis in Three Dimensions Using 320-Row Area Detector Computed Tomography

This study evaluated the effects of the effortful swallow (ES) on pharyngeal cavity volume using three-dimensional kinematic analyses. Nine healthy volunteers (30.7 ± 7.8 years old) underwent a CT scan while swallowing 10 ml of honey thick liquid using no maneuvers (control) and during an ES. Upper and lower volumes (bordered by valleculae) of the pharyngeal air column and the bolus were measured at every frame and were compared between ES and control swallows. Duration of pharyngeal obliteration and the timing of swallowing events were also measured. Maximum volume and volume at the onset of hyoid anterosuperior movement using ES were significantly smaller than those in control swallows (p = 0.012, p = 0.015) in the upper pharynx but not significantly different in lower pharynx. Minimum pharyngeal volume was sustained for a longer time when ES was used compared to control swallows in both upper and lower pharynx (upper p = 0.016, lower p = 0.027). Onset of velopharyngeal closure was earlier when comparing ES and control swallows (p = 0.04). Termination of all events was significantly delayed when the ES was used (p < 0.05). Changes in the upper pharyngeal volume and in the onset of velopharyngeal closure suggest earlier pharyngeal constriction when using the ES. Longer pharyngeal obliteration and prolonged termination of velopharyngeal closure and epiglottis inversion suggest the prolonged pharyngeal constriction during the ES. These findings suggest the ES can be useful for improving the efficiency of swallowing.

Behavioral Interventions Targeting Base of Tongue to Posterior Pharyngeal Wall Approximation: A Scoping Review

Pharyngeal pressure generated by approximation of the base of tongue to the posterior pharyngeal wall (BOT-PPW approximation) is critical for efficient pharyngeal bolus passage and is a frequent goal of dysphagia management. This scoping review evaluated behavioral interventions available to improve BOT-PPW approximation. We searched MEDLINE, CINAHL, Ovid Emcare, Web of Science, SCOPUS, and ProQuest for studies that met the following criteria: (i) behavioral interventions targeting BOT-PPW approximation, which (ii) were assessed using BOT-PPW-specific outcome measures, and (iiia) performed over a period of time (Review Part 1) or (iiib) studied immediate effects (Review Part 2). Study quality was rated using the GRADE framework. Data were extracted and synthesized into dominant themes. Of the 150 studies originally identified, three examined long-term effects (two single cases studies of individuals with dysphagia, and a third study evaluating effortful swallowing in healthy individuals). BOT-PPW approximation only increased in the two single case studies. Twenty-one studies evaluating immediate effects were categorized as follows: (1) effortful swallowing, (2) Mendelsohn maneuver, (3) tongue-hold maneuver, (4) super supraglottic swallowing maneuver, and (5) non-swallowing exercises. Across all studies, varying levels of success in increasing BOT-PPW approximation were reported. Four of 21 immediate effects studies evaluated patients with demonstrated swallowing impairment, whereas 17 studies evaluated healthy adults. Quality assessment revealed low strength of the existing evidence base. The evidence base for rehabilitative interventions targeting BOT-PPW approximation is severely limited and translation is hindered by small sample sizes and methodological limitations. Further clinical research is warranted.

The Effect of Repetitive Transcranial Magnetic Stimulation in Synchronization with Effortful Swallowing on Post-stroke Dysphagia

Either effortful swallowing exercise or repetitive transcranial magnetic stimulation (rTMS) is considered as an effective method to treat dysphagia after stroke. Thus, synchronizing these two interventions may improve the efficiency of treatment. This trial intended to explore the effects of rTMS and effortful swallowing exercise on the recovery of swallowing function in patients after stroke. A total of 56 patients with post-stroke dysphagia who were able to actively cooperate with the training were analyzed in this study. We experimented with different intervention effects of rTMS synchronization with effortful swallowing training (group 1), rTMS (group 2), and traditional swallowing training alone (group 3). Every patient completed conventional swallowing training 5 days a week for 2 weeks. Patients in group 1 and group 2 underwent 10 consecutive sessions of 5 Hz rTMS over the affected mylohyoid cortical region. Fiberoptic endoscopic dysphagia severity scale (FEDSS), penetration/aspiration scale (PAS), standardized swallowing assessment (SSA), and functional oral intake scale (FOIS) were assessed and compared across the groups. No significant difference in FEDSS, PAS, SSA, or FOIS scores was found at baseline among the three groups. The mean change values of the FEDSS score, PAS score, SSA score, and FOIS score between baseline and post-intervention of the three groups (H = 16.05, P < 0.001; H = 21.70, P < 0.001; F (2, 53) = 9.68, P < 0.001; H = 18.26, P < 0.001; respectively) were statistically significant. In addition, the mean change values of FEDSS, PAS, SSA, and FOIS scores in participants in group 1 (all P < 0.001) and group 2 (P = 0.046; P = 0.045; P = 0.028; P = 0.032; respectively) were significantly higher than in group 3. Similarly, the mean change values of FEDSS, PAS, SSA, and FOIS scores were significantly higher in participants in group 1 than in group 2 (P = 0.046; P = 0.038; P = 0.042; P = 0.044; respectively). The results revealed that the conjunction of rTMS and effortful swallowing training was an effective method to facilitate the recovery of swallowing function in stroke patients. The present clinical trial provided a new treatment method for the functional restoration of swallowing in stroke patients, which may further facilitate the recovery of swallowing function in stroke patients with swallowing disorders.

The Effects of Tongue Elevation using a Weighted Plastic Bottle on the Tongue Pressure and Activity of Suprahyoid Muscles

BACKGROUND

A rise in tongue pressure coincides with an increase in the suprahyoid muscles activity.

OBJECTIVES

The aim was to investigate the effects of holding a weighted plastic bottle on tongue pressure and the suprahyoid muscles activity.

METHODS

Eighteen participants (8 men and 10 women; mean age 42 ± 16 years) participated in this study. All participants had no history of speech, language, hearing, or swallowing disorders and no tooth loss, and they did not require dentures. Healthy participants held gauzes connected with a plastic bottle with increasing resistive loads of 0 g, 250 g, 500 g, and 750 g, between their palate and tongue. The maximum tongue pressure and average tongue pressure were measured during a 5-second hold. The average tongue pressure was defined as the mean tongue-pressure data in each task. The suprahyoid muscles activity was measured using the electromyogram (EMG). The root mean square of the EMG signals measured while lifting different loads and while performing the head lifting exercises were compared. All variables were examined using the Friedman's test and Wilcoxon signed-rank test.

RESULTS

The maximum tongue pressure (p < .05) and average tongue pressure values (p < .05) increased gradually in the anterior-median region with increasing resistive loads, and the root mean square amplitudes for 250 g, 500 g, and 750 g were not significant compared to head lifting exercises.

CONCLUSION

These results indicated that Plastic bottle holding could be a potential strength-training tool for the tongue and the suprahyoid muscles.

Effects of Tongue-Strengthening Exercise on Tongue Strength and Effortful Swallowing Pressure in Young Healthy Adults: A Pilot Study

PURPOSE

The purpose of this study was to investigate the effects of tongue-strengthening exercise (TSE) on tongue strength and effortful swallowing pressure in young healthy adults.

METHOD

Thirteen young healthy volunteers (six men, seven women; M _age = 20.5 ± 0.5 years) performed 8 weeks of isometric TSE 3 days per week. A tongue pressure measurement device was used to measure maximum isometric tongue pressure (MITP) and conduct the TSE, and a tactile sensor system attached to the hard palate was used to measure effortful swallowing pressure. MITP and effortful swallowing pressure were measured at baseline, after 4 and 8 weeks of training, and at 4 and 8 weeks after the last training session to examine the detraining effects.

RESULTS

The results indicated that both MITP and effortful swallowing pressure increased significantly from baseline to 8 weeks after training. Although the improved MITP significantly decreased at 4 and 8 weeks after training cessation, no detraining effect was observed for effortful swallowing pressure.

CONCLUSIONS

TSE is an effective method for increasing tongue pressure in wide tongue-palate contact areas during effortful swallow. The effortful swallowing pressure gained with TSE appears to be maintained for at least eight nontraining weeks.

Effect of effortful swallow on pharyngeal pressures during swallowing in adults with dysphagia: A pharyngeal high-resolution manometry study

Purpose: Evidence base to support the use of the effortful swallow in clinical populations with dysphagia is currently lacking. This study aims to quantify the effects of effortful swallowing on pharyngeal swallowing biomechanics in adults with dysphagia using pharyngeal high-resolution manometry (PHRM).Method: ManoScan HRM equipment with a 4.2 mm pressure catheter was used. Participants completed duplicate 10ml baseline and 10ml effortful liquid (IDDSI Level 0) swallows in randomised order. PHRM data were analysed using a semi-automated online platform (www.swallowgateway.com).Result: Fifteen adults (8 males; range 45-86 years) with mixed aetiology dysphagia (Functional Oral Intake Scale Level 2-5) were included. Median pharyngeal contractile (156.81 mmHg cm s; IQR 80.62) increased significantly (213.50 mmHg cm s; IQR 117.2) during effortful swallowing. Significant increases were also observed in velopharyngeal pressure, mesopharyngeal pressure, hypopharyngeal pressure and upper oesophageal sphincter (UOS) relaxation duration. UOS integrated relaxation pressure (IRP) was not significantly altered with effortful swallowing.Conclusion: Effortful swallowing induced significant biomechanical changes to swallow in adults with dysphagia. Increases in global pharyngeal rigour, tongue base pressure and UOS opening duration were captured by PHRM during effortful swallowing. Further investigation in larger homogeneous clinical populations is needed to verify the physiological effects of this frequently employed intervention.

Age-Related Functional Reserve Decline Is Not Seen in Pharyngeal Swallowing Pressures

Purpose Functional reserve represents the difference between an individual's ability to produce a maximum output function and the ability to perform a functional task. Several studies have documented an age-related decrease in functional reserve with oral tongue pressure generation. Whether this pattern is seen in pharyngeal swallowing pressures is unknown. The aim of this study was to investigate pharyngeal functional reserve using high-resolution manometry during normal-effort and effortful swallows. Method Pharyngeal high-resolution manometry was performed on 38 younger healthy individuals (≤ 40 years) and 18 older healthy individuals (≥ 60 years) during normal-effort and effortful water swallows. Pressure metrics included maximum pressure in the velopharynx, tongue base, and hypopharynx, as well as pharyngeal contractile integral and minimum pressure in the upper esophageal sphincter (UES). Repeated-measures analysis of variance was used to determine the effects of swallow task, age, and pharyngeal region on pressure generation. Results Maximum pharyngeal pressures and pharyngeal contractile integral were significantly increased during the effortful swallows compared to normal-effort swallows (p < .001), but there were no interactions between task and age in pharyngeal pressures. In the UES, minimum pressures were significantly elevated in older individuals during effortful swallows compared to normal-effort swallows (p = .007) but did not follow a pattern consistent with reduced functional reserve. Conclusions Healthy individuals increase pharyngeal driving pressures during effortful swallows, without an age-related reduction in the magnitude of pressure increase. Thus, this study did not find evidence for an age-related reduction in pharyngeal functional reserve. The preserved ability to increase pharyngeal pressures during effortful swallowing in aging may support the use of behavioral swallowing interventions in older individuals without neuromuscular conditions. Supplemental Material https://doi.org/10.23641/asha.16606709.

Potential for Behavioural Pressure Modulation at the Upper Oesophageal Sphincter in Healthy Swallowing

Supratentorial structures are known to be involved in the neural control of swallowing, thus the potential for volitional manipulation of pharyngeal swallowing is of rehabilitative interest. The extent of volitional control of the upper oesophageal sphincter (UOS) during swallowing remains unclear. Prior research has shown that the UOS opening duration can be volitionally prolonged during execution of the Mendelsohn manoeuvre, which does not change the UOS opening time in isolation but the swallowing response in its entirety. This study explored the capacity of healthy adults to increase the period of pressure drop in the region of the UOS (UOS-Pdrop) during swallowing, through volitional UOS pressure modulation in the absence of altered pharyngeal pressure. The period of UOS-Pdrop was used as a proxy of UOS opening duration that is associated with a pressure decrease at the region of the UOS. Six healthy adults were seen 45 min daily for 2 weeks and for one follow-up session. During training, high-resolution manometry contour plots were provided for visual biofeedback. Participants were asked to maximally prolong the blue period on the monitor (period of UOS-Pdrop) without altering swallowing biomechanics. Performance was assessed prior to training start and following training. There was evidence within the first session for task-specific volitional prolongation of the period of UOS-Pdrop during swallowing with biofeedback; however, performance was not enhanced with further training. This may suggest that the amount to which the period of UOS-Pdrop may be prolonged is restricted in healthy individuals. The findings of this study indicate a potential of healthy adults to volitionally prolong UOS opening duration as measured by the period of pressure drop at the region of the UOS. Further research is indicated to evaluate purposeful pressure modulation intra-swallow in patient populations with UOS dysfunction to clarify if the specificity of behavioural treatment may be increased.

A comparison of swallow-related submandibular contraction amplitude and duration in people with Parkinson's disease and healthy controls

PURPOSE

To compare the contraction amplitude and contraction duration of submandibular muscles during the pharyngeal stage of swallowing in people with Parkinson's disease (PD) compared to normal controls.

METHOD

A prospective cross-sectional study design was utilised to recruit 24 participants from the regional area. A total of 14 people with PD and 10 healthy controls (HC) were recruited. Participants swallowed three volumes of thin liquid (5mL, 10mL, 15mL) while the activity of the submandibular muscles was recorded using surface electromyography. Measurements of contraction amplitude ratio (normalised to a maximum voluntary contraction) and contraction duration were computed from recorded electromyographic signals. Receiver Operating Characteristics (ROC) were computed for variables associated with significant main effects.

RESULT

Analyses revealed a significant effect of group on contraction amplitude ratio but not contraction duration. There were no significant effects of bolus volume on the dependent variables. ROC analysis indicated that contraction amplitude ratio accurately predicted group assignment in 77% cases.

CONCLUSION

Findings revealed that a majority of people with PD in this study utilised a greater percentage of their maximum contraction force in submandibular muscles when swallowing compared to normal controls. Further research is needed to determine if this inefficiency is consistent across larger samples and whether it is due to elevated baseline muscle activity, a compensatory behaviour to accomplish a more effective swallow, or both.

Diagnosis and treatment of neurogenic dysphagia - S1 guideline of the German Society of Neurology

Introduction

Neurogenic dysphagia defines swallowing disorders caused by diseases of the central and peripheral nervous system, neuromuscular transmission, or muscles. Neurogenic dysphagia is one of the most common and at the same time most dangerous symptoms of many neurological diseases. Its most important sequelae include aspiration pneumonia, malnutrition and dehydration, and affected patients more often require long-term care and are exposed to an increased mortality. Based on a systematic pubmed research of related original papers, review articles, international guidelines and surveys about the diagnostics and treatment of neurogenic dysphagia, a consensus process was initiated, which included dysphagia experts from 27 medical societies.

Recommendations

This guideline consists of 53 recommendations covering in its first part the whole diagnostic spectrum from the dysphagia specific medical history, initial dysphagia screening and clinical assessment, to more refined instrumental procedures, such as flexible endoscopic evaluation of swallowing, the videofluoroscopic swallowing study and high-resolution manometry. In addition, specific clinical scenarios are captured, among others the management of patients with nasogastric and tracheotomy tubes. The second part of this guideline is dedicated to the treatment of neurogenic dysphagia. Apart from dietary interventions and behavioral swallowing treatment, interventions to improve oral hygiene, pharmacological treatment options, different modalities of neurostimulation as well as minimally invasive and surgical therapies are dealt with.

Conclusions

The diagnosis and treatment of neurogenic dysphagia is challenging and requires a joined effort of different medical professions. While the evidence supporting the implementation of dysphagia screening is rather convincing, further trials are needed to improve the quality of evidence for more refined methods of dysphagia diagnostics and, in particular, the different treatment options of neurogenic dysphagia. The present article is an abridged and translated version of the guideline recently published online (https://www.awmf.org/uploads/tx_szleitlinien/030-111l_Neurogene-Dysphagie_2020-05.pdf).

Electromyographic activation patterns during swallowing in older adults

Age-related weakness due to atrophy and fatty infiltration in oropharyngeal muscles may be related to dysphagia in older adults. However, little is known about changes in the oropharyngeal muscle activation pattern in older adults. This was a prospective and experimental study. Forty healthy participants (20 older [> 60 years] and 20 young [< 60 years] adults) were enrolled. Six channel surface electrodes were placed over the bilateral suprahyoid (SH), bilateral retrohyoid (RH), thyrohyoid (TH), and sternothyroid (StH) muscles. Electromyography signals were then recorded twice for each patient during swallowing of 2 cc of water, 5 cc of water, and 5 cc of a highly viscous fluid. Latency, duration, and peak amplitude were measured. The activation patterns were the same, in the order of SH, TH, and StH, in both groups. The muscle activation patterns were classified as type I and II; the type I pattern was characterized by a monophasic shape, and the type II comprised a pre-reflex phase and a main phase. The oropharyngeal muscles and SH muscles were found to develop a pre-reflex phase specifically with increasing volume and viscosity of the swallowed fluid. Type I showed a different response to the highly viscous fluid in the older group compared to that in the younger group. However, type II showed concordant changes in the groups. Therefore, healthy older people were found to compensate for swallowing with a pre-reflex phase of muscle activation in response to increased liquid volume and viscosity, to adjust for age-related muscle weakness.

Effect of Volitional Effort on Submental Surface Electromyographic Activity During Healthy Swallowing

The effortful swallowing technique aims to compensate for or rehabilitate impaired swallowing by using maximal volitional effort to behaviorally modify aspects of swallowing physiology. Given that swallowing is a submaximal task, swallowing at submaximal levels has recently been suggested as a more task-specific therapeutic technique. The aim of this study was to investigate differences in muscle activity during minimum, regular, and maximum effort swallowing of different boluses and across different ages, with the goal of characterizing the task specificity of minimum effort and maximum effort swallowing. Forty-three healthy adults (22 female) representing four age groups (20-39, 40-59, 60-79, and 80 + years) participated in the study. They were verbally cued to swallow saliva and 5 mL water boluses using participant-determined minimum, regular, and maximum levels of effort, in randomized order. sEMG peak amplitude and duration of each swallow were measured. Linear mixed effects analyses demonstrated that compared to regular effort swallowing, maximum effort swallowing resulted in increased sEMG amplitude (p < .001) and prolonged duration (p < .001), while minimum effort swallowing resulted in decreased amplitude (p < .001) but no significant difference in duration (p = .06). These effects occurred regardless of age or bolus type. Differences in sEMG activity were smaller between regular and minimum effort swallowing than regular and maximum effort swallowing. Both increasing and decreasing volitional efforts during swallowing translate to significant modulation of muscle activity. However, regular swallowing is more similar to minimal effort swallowing. Results reinforce the concept of swallowing as a submaximal task, and provide insight into the development of sEMG biofeedback techniques for rehabilitation.

The Influence of Surface Electromyography Visual and Clinician Verbal Feedback on Swallow Effort Ratio at Different Bolus Volumes in a Healthy Population

BACKGROUND/AIMS

The effortful swallow is a common treatment intervention requiring increased intensity to facilitate adaptations and modify swallow kinematics. The type of feedback and bolus volume provided may influence the intensity of the effortful swallow. To determine the increased effortful swallow intensity, a clinician can collect the peak amplitude of an effortful swallow and a typical swallow and compute a "swallow effort ratio" (SER). Dividing the effortful swallow surface electromyography (sEMG) peak amplitude by the typical swallow sEMG peak amplitude derives the SER. A higher SER suggests increased intensity. An increase in the SER may have clinical relevance in swallowing therapy as a threshold of intensity is required to elicit neuroplastic change. The purpose of this investigation was to determine whether sEMG visual and clinician verbal feedback increases the SER. Additionally, the investigation examined whether the SER is influenced by different liquid bolus volumes.

METHODS

Eighty-two nondysphagic, healthy adults were assigned at random to 2 groups. One group received no feedback, and the other received verbal and visual feedback while performing typical and effortful swallows at 3 liquid volumes.

RESULTS

An analysis of covariance compared the typical and effortful peak swallow amplitudes among 3 volumes in the 2 feedback groups. There was a significant effect on the peak amplitude values by feedback group F(2, 79) = 22.82, p < 0.001. There were no differences in peak amplitude by volume regardless of feedback F(2, 78) = 0.413, p = 0.663.

CONCLUSION

It appears that sEMG visual and clinician verbal feedback increases the SER, which may be a surrogate for intensity. An increased SER may have a positive effect on swallow intervention as intensity is known to influence outcomes of exercise and elicit neuroplastic change.

A Systematic Review of the Physiological Effects of the Effortful Swallow Maneuver in Adults With Normal and Disordered Swallowing

Purpose This systematic review summarizes the biomechanical and functional effects of the effortful swallow in adults with and without dysphagia, highlighting clinical implications and future research needs. Specifically, the effects of the effortful swallow on swallowing physiology, safety, and efficiency were identified, as well as the strengths and limitations of current research. Method Recommendations specified by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses were followed. A literature search of three databases and relevant articles cited in the searched studies was performed. Two evaluators independently analyzed the studies for eligibility criteria, and final inclusion of studies was decided by consensus. Evaluators also assessed each study for quality of evidence. Results Twenty-three studies were included in this systematic review. Main findings indicated that the effortful swallow generated greater pressures in the tongue-to-palate, pharynx, upper esophageal sphincter, and esophageal regions. Inconsistent results for hyolaryngeal excursion were reported, as well as for swallowing function. Instructions of the effortful swallow varied greatly across studies. Two of the 23 studies were judged to be of high quality, and the remaining studies were of medium quality based on the quality indicators of this review. Conclusions Biomechanical effects of the effortful swallow included increased pressures in the oral, pharyngeal, and esophageal regions. Future investigations should address the effects of the effortful swallow in individuals with dysphagia and its potential role as a rehabilitative maneuver. Moreover, standardization of the effortful swallow instructions based on its physiological and functional effects is essential.

Systematic Effortful Swallowing Exercise Without External Resistance Does Not Increase Swallowing-Related Muscle Strength in the Elderly

Effortful swallow (ES) is a maneuver intended to increase pressure on a bolus by swallowing and pushing with sufficient force to facilitate clearance. Although ES is mainly known for its immediate effects, the long-term effects of applying ES as an exercise program remain unclear. This study investigated the effects of a 7-week systematic ES exercise regime on swallowing-related muscle strength in individuals aged 65 years and over. In total, 30 healthy older adults participated in this study (16 women and 14 men, aged 67-90 years). The subjects participated in the exercise program for 20 min a day, twice a week, for 7 weeks. To gradually increase exercise intensity, the number of exercises per session was increased from the initial 60 repetitions (weeks 1-2) to 120 repetitions (weeks 5-7). To measure the effect of the strengthening exercise program, the activation level of suprahyoid muscles was measured using surface electromyography, and a tongue pressure measurement system was used to measure variables related to tongue strength (isometric tongue pressure, swallowing tongue pressure, and tongue endurance). Although the effect of ES exercise on muscle strength through gradual adjustment of exercise frequency was not confirmed, ES remains valuable as an exercise for strengthening the muscles involved in swallowing. Future studies are warranted to determine the effects of ES exercise after adjusting for other variables of exercise intensity.

Surface Electromyographic Biofeedback and the Effortful Swallow Exercise for Stroke-Related Dysphagia and in Healthy Ageing

Dysphagia is common after stroke, leading to adverse outcome. The Effortful Swallow (ES) is recommended to improve swallowing but it is not known if dysphagic patients can increase muscle activity during the exercise or if age affects performance. Providing surface electromyographic (sEMG) biofeedback during dysphagia therapy may enhance exercise completion, but this has not been investigated and the technique’s acceptability to patients is not known. Aims: To determine if age or post-stroke dysphagia affect the ability to increase submental muscle activity during the ES, if sEMG biofeedback improves ES performance and if sEMG is an acceptable addition to therapy. In a Phase I study submental sEMG amplitudes were measured from 15 people with dysphagia < 3 months post-stroke and 85 healthy participants aged 18–89 years during swallowing (NS) and when they performed the ES with and without sEMG biofeedback. Participant feedback was collected via questionnaire. Measurements were compared with repeated measures ANOVA and age effects were examined with linear regression. Both groups produced significantly greater muscle activity for the ES than NS (p < 0.001) and significantly increased activity with biofeedback (p < 0.001) with no effect of age. Participant feedback about sEMG was very positive; over 98% would be happy to use it regularly. The ES is a physiologically beneficial dysphagia exercise, increasing muscle activity during swallowing. sEMG biofeedback further enhances performance and is considered an acceptable technique by patients. These findings support the potential application of sEMG biofeedback and the ES in dysphagia therapy in stroke, justifying further investigation of patient outcome.

Effects of sitting posture and bolus volume on activation of swallowing-related muscles

BACKGROUND

The pharyngeal phase is a particularly important clinical factor related to swallowing dysfunctions. Head and neck posture, as well as bolus volume, are important factors affecting the pharyngeal stages of normal swallowing.

OBJECTIVE

The aim of our study was to identify the effects of sitting posture and bolus volume on the activation of swallowing-related muscles.

MATERIALS AND METHODS

Twenty-four subjects participated in the study. The subjects were positioned in three sitting postures-slump sitting (SS), lumbo-pelvic upright sitting (LUS), and thoracic upright sitting (TUS). While sitting in the chair, the subject was instructed to swallow 10 and 20 mL of water. Surface electromyography (EMG) was used to measure the muscle activity of the supra-hyoid (SH) and infra-hyoid (IH) muscles. Also, sitting posture alignment (head, cervical and shoulder angle) was also performed. Data were analysed with a repeated measures analysis of variance (RMANOVA) using a generalised linear model.

RESULTS

There was no significant difference in terms of the head angle (P = .395). However, significant differences were found in relation to the cervical angle (P < .001) and shoulder angle (P < .001). The TUS produced the lowest SH EMG activity (P = .001), in comparison to SS and LUS. The bolus volume for 20 mL showed greater SH and IH EMG activity (P < .001) than did the bolus volume for 10 mL.

CONCLUSIONS

Correcting sitting posture from SS to TUS may better assist swallowing-related muscles with less effort, irrespective of the bolus volume.

Effect of effortful swallowing training on tongue strength and oropharyngeal swallowing function in stroke patients with dysphagia: a double-blind, randomized controlled trial

BACKGROUND

Effortful swallowing training (EST) is a remedial method for the training of swallowing-related muscles in the oropharyngeal phase. However, clinical evidence of its effectiveness is insufficient.

AIMS

To investigate the effects of EST on tongue strength and swallowing function in patients with stroke.

METHODS & PROCEDURES

Stroke patients with dysphagia were randomly assigned to one of two groups: an experimental group (n = 12) and a control group (n = 12). The experimental group underwent EST, while the control group performed saliva swallowing. Training was conducted 5 days per week for 4 weeks. Both groups underwent conventional dysphagia treatment for 30 min/day, 5 days/week for 4 weeks.

OUTCOMES & RESULTS

Tongue strength was assessed using the Iowa Oral Performance Instrument. The Videofluoroscopic Dysphagia Scale (VDS), based on a videofluoroscopic swallowing study, was used to analyze oropharyngeal swallowing function. The experimental group showed greater improvements in anterior and posterior tongue strength compared with the control group (p = 0.046 and 0.042, respectively), and greater improvement in the oral phases of the VDS (p = 0.017).

CONCLUSIONS & IMPLICATIONS

We recommend EST as a remedial strategy for improving tongue strength and oral swallowing function in patients with stroke.

Does Therapy With Biofeedback Improve Swallowing in Adults With Dysphagia? A Systematic Review and Meta-Analysis

OBJECTIVE

To describe and systematically review the current evidence on the effects of swallow therapy augmented by biofeedback in adults with dysphagia (PROSPERO 2016:CRD42016052942).

DATA SOURCES

Two independent reviewers conducted searches that included MEDLINE, EMBASE, trial registries, and gray literature up to December 2016.

STUDY SELECTION

Randomized controlled trials (RCTs) and non-RCTs were assessed, including for risk of bias and quality.

DATA EXTRACTION

Data were extracted by 1 reviewer and verified by another on biofeedback type, measures of swallow function, physiology and clinical outcome, and analysed using Cochrane Review Manager (random effects models). Results are expressed as weighted mean difference (WMD) and odds ratio (OR).

DATA SYNTHESIS

Of 675 articles, we included 23 studies (N=448 participants). Three main types of biofeedback were used: accelerometry, surface electromyography (sEMG), and tongue manometry. Exercises included saliva swallows, maneuvers, and strength exercises. Dose varied between 6 and 72 sessions for 20-60 minutes. Five controlled studies (stroke n=95; head and neck cancer n=33; mixed etiology n=10) were included in meta-analyses. Compared to control, biofeedback augmented dysphagia therapy significantly enhanced hyoid displacement (3 studies, WMD=0.22cm; 95% confidence interval [CI] [0.04, 0.40], P=.02) but there was no significant difference in functional oral intake (WMD=1.10; 95% CI [-1.69, 3.89], P=.44) or dependency on tube feeding (OR =3.19; 95% CI [0.16, 62.72], P=.45). Risk of bias was high and there was significant statistical heterogeneity between trials in measures of swallow function and number tube fed (I² 70%-94%). Several nonvalidated outcome measures were used. Subgroup analyses were not possible due to a paucity of studies.

CONCLUSIONS

Dysphagia therapy augmented by biofeedback using sEMG and accelerometry enhances hyoid displacement but functional improvements in swallowing are not evident. However, data are extremely limited and further larger well-designed RCTs are warranted.

Evaluation of normal swallowing functions by using dynamic high-density surface electromyography maps

BACKGROUND

Swallowing is a continuous process with substantive interdependencies among different muscles, and it plays a significant role in our daily life. The aim of this study was to propose a novel technique based on high-density surface electromyography (HD sEMG) for the evaluation of normal swallowing functions.

METHODS

A total of 96 electrodes were placed on the front neck to acquire myoelectric signals from 12 healthy subjects while they were performing different swallowing tasks. HD sEMG energy maps were constructed based on the root mean square values to visualize muscular activities during swallowing. The effects of different volumes, viscosities, and head postures on the normal swallowing process were systemically investigated by using the energy maps.

RESULTS

The results showed that the HD sEMG energy maps could provide detailed spatial and temporal properties of the muscle electrical activity, and visualize the muscle contractions that closely related to the swallowing function. The energy maps also showed that the swallowing time and effort was also explicitly affected by the volume and viscosity of the bolus. The concentration of the muscular activities shifted to the opposite side when the subjects turned their head to either side.

CONCLUSIONS

The proposed method could provide an alternative method to physiologically evaluate the dynamic characteristics of normal swallowing and had the advantage of providing a full picture of how different muscle activities cooperate in time and location. The findings from this study suggested that the HD sEMG technique might be a useful tool for fast screening and objective assessment of swallowing disorders or dysphagia.

Differential Response Pattern of Oropharyngeal Pressure by Bolus and Dry Swallows

The aim of this study was to determine if bolus and dry swallow showed similar pressure changes in the oropharynx using our newly developed device. A unique character of it includes that baropressure can be measured with the sensor being placed in the balloon and can assess the swallowing mechanics in terms of pressure changes in the oropharynx with less influences of direct contacts of boluses and oropharyngeal structures during swallow indirectly. Fifteen healthy subjects swallowed saliva (dry), 15 ml of water, 45 ml of water, and 15 ml of two different types of food in terms of viscosity (potage soup-type and mayonnaise-type foods). Suprahyoid muscle activity was recorded simultaneously. Three parameters, area under the curve (AUC), peak amplitude, and duration of pressure, were analyzed from each swallow. Almost all of the bolus swallowing events had biphasic baropressure responses consisting of an early phase and late phase (99%), whereas 90% of the saliva swallowing events had a single phase. AUC, peak, and duration displayed greater effects during the late phase than during the early phase. Baropressure of the early phase, but not of the late phase, significantly increased with increasing volume; however, small but significant viscosity effects on pressure were seen during both phases. Peak pressure of the late phase was preceded by maximum muscle activity, whereas that of the early phase was seen when muscle activity displayed a peak response. These findings indicated that our device with the ability to measure baropressure has the potential to provide additional parameter to assess the swallow physiology, and biphasic baropressure responses in the early and late phases could reflect functional aspects of the swallowing reflexes.

Biomechanical Quantification of Mendelsohn Maneuver and Effortful Swallowing on Pharyngoesophageal Function

Objective

To quantify the effects of 2 swallowing maneuvers used in dysphagia rehabilitation—the Mendelsohn maneuver and effortful swallowing—on pharyngoesophageal function with novel, objective pressure-flow analysis.

Study Design

Evaluation of intervention effects in a healthy control cohort.

Setting

A pharyngoesophageal motility research laboratory in a tertiary education facility.

Subjects

Twelve young healthy subjects (9 women, 28.6 ± 7.9 years) from the general public, without swallowing impairment, volunteered to participate in this study.

Methods

Surface electromyography from the floor-of-mouth musculature and high-resolution impedance manometry–based pressure flow analysis were used to assess floor-of-mouth activation and pharyngoesophageal motility, respectively. Subjects each performed 10 noneffortful control swallows, Mendelsohn maneuver swallows, and effortful swallows, with a 5-mL viscous bolus. Repeated measures analyses of variance was used to compare outcome measures across conditions.

Results

Effortful and Mendelsohn swallows generated greater floor-of-mouth contraction ( P = .001) and pharyngeal pressure ( P < .0001) when compared with control swallows. There were no changes at the level of the upper esophageal sphincter, except for a faster opening to maximal diameter during maneuver swallows ( P = .01). The proximal esophageal contractile integral was reduced during Mendelsohn swallows ( P = .001).

Conclusion

Effortful and Mendelsohn maneuver swallows significantly alter the pharyngoesophageal pressure profile. Faster opening of the upper esophageal sphincter may facilitate bolus transfer during maneuver swallows; however, reduced proximal esophageal contractility during Mendelsohn maneuver swallows may impair bolus flow and aggravate dysphagic symptoms.

Identification of the most significant electrode positions in electromyographic evaluation of swallowing-related movements in humans

Surface electromyography (sEMG) is a well-established procedure for recording swallowing-related muscle activities. Because the use of a large number of sEMG channels is time consuming and technically sophisticated, the aim of this study was to identify the most significant electrode positions associated with oropharyngeal swallowing activities. Healthy subjects (N = 16) were tested with a total of 42 channels placed in M. masseter, M. orbicularis oris, submental and paralaryngeal regions. Each test subject swallowed 10 ml of water five times. After having identified 16 optimal electrode positions, that is, positions with the strongest signals quantified by the highest integral values, differences to 26 other ones were determined by a Mann-Whitney U test. Kruskal-Wallis H test was utilized for the analysis of differences between single subjects, subject subgroups, and single electrode positions. Factors associated with sEMG signals were examined in a linear regression. Sixteen electrode positions were chosen by a simple ranking of integral values. These positions delivered significantly higher signals than the other 26 positions. Differences between single electrode positions and between test subjects were also significant. Sixteen most significant positions were identified which represent swallowing-related muscle potentials in healthy subjects.

Non-invasive Assessment of Swallowing and Respiration Coordination for the OSA Patient

The objectives of this study are to investigate swallowing and its coordination with respiration in patients with obstructive sleep apnea (OSA). This is a prospective cohort study conducted in a tertiary referred Medical Center. A non-invasive method of assessing swallowing was used to detect the oropharyngeal swallowing parameters and the coordination with respiration during swallowing. The system used to assess swallowing detected: (1) movement of the larynx using a force-sensing resistor; (2) submental muscle activity using surface electromyography; and (3) coordination with respiration by measuring nasal airflow. Five sizes of water boluses (maximum 20 mL) were swallowed three times, and the data recorded and analyzed for each participant. Thirty-nine normal controls and 35 patients with OSA who fulfilled the inclusion criteria were recruited. The oropharyngeal swallowing parameters of the patients differed from the controls, including longer total excursion duration and shorter duration of submental muscles contraction. A longer swallowing respiratory pause (SRP), temporary coordination with respiration during swallowing, was demonstrated in the patients compared with the controls. The frequency of non-expiratory/expiratory pre- and postswallowing respiratory phase patterns of the patients was similar with the controls. There was significantly more piecemeal deglutition in OSA patients when clumping 10- and 20-mL water boluses swallowing together (p = 0.048). Oropharyngeal swallowing and coordination with respiration affected patients with OSA, and it could be detected using a non-invasive method. The results of this study may serve as a baseline for further research and help advance research methods in obstructive sleep apnea swallowing studies.

Effects of tongue pressing effortful swallow in older healthy individuals

INTRODUCTION

The risk of swallowing disorders is increased for older individuals due to weak tongue and pharyngeal muscle strength. This study was appraised the value of a preventative approach by developing the tongue pressing effortful swallow (TPES) applied using a home-based and self-administered procedure. The TPES was developed by combining two swallowing exercises: tongue strengthening exercise and the effortful swallow. The purpose of this study was to examine the effects of the TPES on maximum tongue pressure and peak amplitude of submental muscle activity in older individuals.

MATERIAL AND METHODS

27 older individuals (mean 73 years) performed a 4-week TPES. The exercise program was adapted to a home-based and self-administered procedure. The maximum tongue pressure was measured by the Iowa Oral Performance Instrument and peak amplitude of submental muscle activity by surface electromyography (sEMG). Statistical comparisons were made by a matched pairs t-test (p<0.05).

RESULTS

The results of this study showed that the TPES had statistically significant and positive effects on increasing maximum tongue pressure, but the peak amplitude of the submental sEMG did not differ between before and after exercises.

CONCLUSIONS

The TPES had a positive impact in older individuals. The TPES, a combining exercise, was possible because two exercises had common physiological events. The TPES was a more innovative and efficient approach than the tongue strengthening exercise alone. In addition, older individuals were able to perform the swallowing exercise at home and by themselves with little assistance. Future research needs to refine the TPES and apply it to patients with dysphagia.

Expanding Instrumental Options for Dysphagia Diagnosis and Research: Ultrasound and Manometry

Diagnostic assessment of swallowing in routine clinical practice relies heavily on the long-standing techniques of videofluoroscopic swallowing study (VFSS) and videoendoscopic evaluation of swallowing (VEES). These complementary and sophisticated techniques provide a real-time visualization of biomechanical movements of the structures involved in swallowing and consequent effects on bolus flow. Despite the sophistication of this instrumentation, interpretation relies heavily on subjective clinical judgement and temporal resolution is limited, limitations that may influence patient management. Adjunctive diagnostic assessments may be utilized to compensate for the limitations posed by VFSS and VEES. Ultrasound and pharyngeal manometry do not represent the latest in technological advances, with both emerging in swallowing research over 20 years ago. However, both have resisted integration into routine clinical practice, despite the fact that they offer quantitative metrics of swallowing that are not available using standard techniques. The aim of this review is to present recent research on these two less frequently used modalities in clinical swallowing assessment, discuss potential applications in clinical practice and review supportive data on test-retest reliability, rater reliability and validity. The paper will conclude with a case report that exemplifies the unique contribution of these modalities in executing and revising therapeutic approaches for a patient with neurogenic dysphagia.

A Pilot Study of the Tongue Pull-Back Exercise for Improving Tongue-Base Retraction and Two Novel Methods to Add Resistance to the Tongue Pull-Back

This pilot study investigated the tongue pull-back (TPB) exercise to improve tongue-base retraction as well as two methods to add resistance to the TPB. Surface electromyography (sEMG) to the submental triangle was used as an indication of tongue-base activity on 13 healthy adults during: (1) saliva swallow, (2) 15 mL water swallow, (3) effortful swallow, (4) unassisted TPB, (5) TPB with added resistance by holding the tongue with gauze (finger-resisted TPB), and (6) TPB with the tongue clipped to a spring-loaded tension resistance device (device-resisted TPB). Order of the exercises was randomized. The exercises fell into two groups-weak and intense. Weak exercises included saliva swallow, water swallow, and unassisted TPB (mean sEMG = 19.07 μV, p = .593). Intense exercises included effortful swallow, finger-resisted TPB, and device-resisted TPB (mean sEMG = 36.44 μV, p = .315). Each intense exercise resulted in significantly higher mean sEMG peak amplitude than each weak exercise (p < .05), with one exception; the effortful swallow was not significantly different than the unassisted TPB (p = .171). This study provides preliminary evidence that the unassisted TPB may not be any more helpful for improving tongue-base retraction than normal swallowing. Adding resistance to the TPB by holding the tongue with gauze may be an effective alternative. This study also demonstrates proof-of-concept for creating a device to attach to the tongue and provide tension resistance during the TPB exercise. Further research with a more sophisticated design is needed before such a device can be fully developed and implemented clinically.

Visuomotor control of neck surface electromyography in Parkinson's disease

OBJECTIVE

To compare performance of individuals with Parkinson's disease (PD) and age-matched controls on a visuomotor tracking task controlled via surface electromyography (sEMG).

METHODS

Twenty-seven adults with PD and twenty-four older controls produced dry swallows and completed a visuomotor tracking task utilizing both static and dynamic targets. sEMG was recorded at the anterior neck and submental surface during both tasks.

RESULTS

There was no significant difference in visuomotor tracking ability between cohorts. Post hoc analyses indicated that there was no significant difference between participant groups in the strength or duration of swallows as measured by sEMG but that participants with PD showed a trend for decreased swallow durations at the anterior neck (padj = 0.067) whereas controls showed a trend for increased durations at the anterior neck (padj = 0.112), compared to the submental surface. However, there were no significant correlations between swallowing behavior and visuomotor tracking ability.

CONCLUSION

There were no significant differences in visuomotor tracking performance between individuals with PD and controls. Furthermore, there was no relationship between tracking ability and swallowing behavior. We conclude that sEMG-mediated biofeedback may have limited promise as a tool for treating PD-related dysphagia.

Effects of Lingual Effort on Swallow Pressures Following Radiation Treatment

PURPOSE

This article investigated the effects of increased oral lingual pressure on pharyngeal pressures during swallowing in patients who have undergone radiotherapy for head and neck cancer. It was hypothesized that increased oral lingual pressure would result in increased pharyngeal pressures.

METHOD

A within-subject experimental design was used with 20 participants who were status post external beam radiotherapy for head and neck cancer. Participants completed typical swallows and swallows with increased lingual force during manofluoroscopic swallow studies. The swallow condition order was randomized across participants.

RESULTS

Manometric data revealed significant differences in swallow pressure by condition at the base of tongue and upper esophageal sphincter sensor locations without significant pressure differences in the lower pharynx. The effortful lingual swallows resulted in higher mean pressures at all locations.

CONCLUSIONS

The results of this study suggest that use of a maneuver designed to increase oral tongue effort can also increase pharyngeal tongue base pressure. Therefore, therapeutic activities used to generate greater pressure of the oral tongue may also alter pharyngeal response. Further research is needed to determine the direct clinical effect on swallow function for individuals with head and neck cancer.

Effortful swallow enhances vertical hyolaryngeal movement and prolongs duration after maximal excursion

Effortful swallowing (EFS) is a common compensatory swallowing manoeuver for dysphagia patients. We investigated the influence of EFS on temporal and spatial characteristics of the movements of the hyoid bone, larynx and epiglottis in healthy subjects. A total of 41 volunteers swallowed 10 mL of diluted barium solution using two swallowing strategies: usual and effortful swallowing (USS and EFS). The motions of the hyoid bone, larynx and epiglottis were tracked using frame-by-frame kinematic motion analysis of videofluoroscopic images. Maximal velocities and maximal displacements of hyoid and larynx, the maximal angle of the epiglottic tilt, and the durations of hyoid excursion, laryngeal elevation and epiglottic tilt were measured. Compared to USS, EFS was associated with significantly greater vertical displacement of the hyoid (P < 0.001), vertical and horizontal displacement of the larynx (P = 0.003, P = 0.019), and maximal angle of the epiglottic tilt (P = 0.001). In addition, the durations of the vertical and horizontal excursions of the hyoid, vertical excursion of the larynx and the epiglottic tilt were greater in EFS, compared with USS. Effortful swallowing was also associated with significantly greater maximum velocities of the hyoid and larynx during swallowing. In conclusion, the EFS manoeuver facilitates vertical speed and distance of hyolaryngeal excursion and epiglottic tilt and extends the duration of excursion and the epiglottic tilt, especially after reaching maximal excursion in healthy subjects. These results confirm the temporal and kinematic benefits of airway protection induced by the EFS manoeuver.

Dysphagia--a common, transient symptom in critical illness polyneuropathy: a fiberoptic endoscopic evaluation of swallowing study*

OBJECTIVES

Critical illness polyneuropathy is a common disorder in the neurological ICU. Dysphagia is well known to deteriorate outcome in the ICU. The prevalence of dysphagia in critical illness polyneuropathy is not known. The aim of this study was to evaluate the prevalence of dysphagia in critical illness polyneuropathy using fiberoptic endoscopic evaluation of swallowing.

DESIGN

Prospective, cohort study.

SETTING

Neurological rehabilitation ICU.

PATIENTS

Twenty-two patients with critical illness polyneuropathy.

INTERVENTIONS

Clinical swallowing examination and serial fiberoptic endoscopic evaluation of swallowing (days 3, 14, and 28 after admission).

MEASUREMENTS AND MAIN RESULTS

Swallowing of saliva, pureed consistencies, and liquids was tested using fiberoptic endoscopic evaluation of swallowing at three different time points. The penetration-aspiration scale by Rosenbek et al and the secretion severity rating scale by Murray et al were used for grading. Functional outcome after rehabilitation was assessed using the functional independence measure.: Pathologic swallowing was found in 20 of 22 patients (91%). Hypesthesia of laryngeal structures was found in 17 of 22 patients (77%) during the first fiberoptic endoscopic evaluation of swallowing. Over the 4-week follow-up period, laryngeal hypesthesia resolved in 75% of affected cases. Pureed consistencies were swallowed safely in 18 of 22 cases (82%), whereas liquids and saliva showed high aspiration rates (13 of 17 [78%] and 10 of 22 [45%], respectively). Swallowing function recovered completely in 21 of 22 (95%) within 4 weeks.

CONCLUSIONS

Dysphagia is frequent among patients with critical illness polyneuropathy treated in the ICU. Old age, chronic obstructive pulmonary disease, the mode of mechanical ventilation, the prevalence of tracheal tubes, and behavioral "learned nonuse" may all be contributing factors for the development of dysphagia in critical illness polyneuropathy. Complete recovery occurs in a high percentage of affected individuals within 4 weeks.

Dysphagia Management in Acute and Sub-acute Stroke

Swallowing dysfunction is common after stroke. More than 50% of the 665 thousand stroke survivors will experience dysphagia acutely of which approximately 80 thousand will experience persistent dysphagia at 6 months. The physiologic impairments that result in post-stroke dysphagia are varied. This review focuses primarily on well-established dysphagia treatments in the context of the physiologic impairments they treat. Traditional dysphagia therapies including volume and texture modifications, strategies such as chin tuck, head tilt, head turn, effortful swallow, supraglottic swallow, super-supraglottic swallow, Mendelsohn maneuver and exercises such as the Shaker exercise and Masako (tongue hold) maneuver are discussed. Other more recent treatment interventions are discussed in the context of the evidence available.